2004 INFINITI FX35 mass air flow sensor

TROUBLE DIAGNOSIS
EC-755
[VK45DE]
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Revision: 2004 November 2004 FX35/FX4535 BRHeated oxygen sensor 1
(bank 2)[Engine is running]
Warm-up condition

Engine speed is 2,000 rpm0 - Approximately 1.0V
(Periodically change)
36 W Knock sensor 2[Engine is running]

Idle speedApproximately 2.5V
45 WEVAP canister purge vol-
ume control solenoid valve[Engine is running]

Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed is about 2,000 rpm (More
than 100 seconds after starting engine)11 - 1 4 V
46
60
61
62
65
79
80
81L
SB
L
Y
Y
LG
GY
GIgnition signal No. 7
Ignition signal No. 5
Ignition signal No. 3
Ignition signal No. 1
Ignition signal No. 8
Ignition signal No. 6
Ignition signal No. 4
Ignition signal No. 2[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle0 - 0.2V
[Engine is running]

Warm-up condition

Engine speed is 2,000 rpm0.1 - 0.4V
47 LSensor power supply
(Throttle position sensor)[Ignition switch: ON]Approximately 5V
48 LSensor power supply
(Mass air flow sensor /
EVAP control system pres-
sure sensor)[Ignition switch: ON]Approximately 5V
49 PUSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB0050E
PBIB0051E
PBIB0044E
PBIB0045E

EC-756
[VK45DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
50 W Throttle position sensor 1[Ignition switch: ON]

Engine stopped

Shift lever position is D

Accelerator pedal is fully releasedMore than 0.36V
[Ignition switch: ON]

Engine stopped

Shift lever position is D

Accelerator pedal is fully depressedLess than 4.75V
51 L/W Mass air flow sensor[Engine is running]

Warm-up condition

Idle speed1.2 - 1.8V
[Engine is running]

Warm-up condition

Engine speed is 2,500 rpm1.7 - 2.4V
53 R/LIntake valve timing control
position sensor (bank 2)[Engine is running]

Warm-up condition

Idle speed0 - 1.0V
[Engine is running]

Engine speed is 2,000 rpm0 - 1.0V
55 W/RHeated oxygen sensor 2
(bank 1)[Engine is running]

Warm-up condition

Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
–After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load0 - Approximately 1.0V
66 BSensor ground
(Throttle position sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
67 B/WSensor ground
(Mass air flow sensor / IAT
sensor / Power steering
pressure sensor / EVAP
control system pressure
sensor / Refrigerant pres-
sure sensor / ECT sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
68 SBSensor power supply
(Power steering pressure
sensor)[Ignition switch: ON]Approximately 5V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB2046E

TROUBLE DIAGNOSIS
EC-761
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
ItemDIAGNOSTIC TEST MODE
WORK
SUP-
PORTSELF-DIAGNOS-
TIC RESULTS
DATA
MONI-
TORDATA
MONI-
TOR
(SPEC)ACTIVE
TESTDTC & SRT
CONFIRMATION
DTC*1FREEZE
FRAME
DATA*2SRT
STATUSDTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS)××××
Camshaft position sensor
(PHASE)××××
Mass air flow sensor×××
Engine coolant temperature sen-
sor×××××
Heated oxygen sensor 1×××××
Heated oxygen sensor 2×××××
Wheel sensor××××
Accelerator pedal position sensor×××
Throttle position sensor×××
Fuel tank temperature sensor××××
EVAP control system pressure
sensor×××
Intake air temperature sensor××××
Knock sensor×
Refrigerant pressure sensor××
Closed throttle position switch
(accelerator pedal position sensor
signal)××
Air conditioner switch××
Park/neutral position (PNP) switch×××
Stop lamp switch×××
Power steering pressure sensor×××
Battery voltage××
Load signal××
Snow mode switch××
Intake valve timing control position
sensor×××
Fuel level sensor×××
ICC steering switch×××
ASCD steering switch×××
ICC brake switch×××
ASCD brake switch×××

TROUBLE DIAGNOSIS
EC-765
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
*: The items are the same as those of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×: Applicable B/FUEL SCHDL
[msec]

The base fuel schedule at the moment a malfunction is detected is displayed.
INT/A TEMP SE [°C]
or [°F]

The intake air temperature at the moment a malfunction is detected is displayed. Freeze frame data
item*Description
Monitored item [Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks
ENG SPEED [rpm]××

Indicates the engine speed computed from
the signal of the crankshaft position sensor
(POS) and camshaft position sensor
(PHASE).
Accuracy becomes poor if engine
speed drops below the idle rpm.

If the signal is interrupted while the
engine is running, an abnormal value
may be indicated.
MAS A/F SE-B1 [V]××

The signal voltage of the mass air flow sen-
sor is displayed.
When the engine is stopped, a cer-
tain value is indicated.
B/FUEL SCHDL
[msec]×

“Base fuel schedule” indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board correc-
tion.
A/F ALPHA-B1 [%]×

The mean value of the air-fuel ratio feed-
back correction factor per cycle is indicated.

When the engine is stopped, a cer-
tain value is indicated.

This data also includes the data for
the air-fuel ratio learning control. A/F ALPHA-B2 [%]×
COOLAN TEMP/S
[°C] or [°F]××

The engine coolant temperature (deter-
mined by the signal voltage of the engine
coolant temperature sensor) is displayed.

When the engine coolant tempera-
ture sensor is open or short-circuited,
ECM enters fail-safe mode. The
engine coolant temperature deter-
mined by the ECM is displayed.
HO2S1 (B1) [V]××

The signal voltage of the heated oxygen
sensor 1 is displayed.
HO2S1 (B2) [V]×
HO2S2 (B1) [V]×

The signal voltage of the heated oxygen
sensor 2 is displayed.
HO2S2 (B2) [V]×
HO2S1 MNTR (B1)
[RICH/LEAN]××

Display of heated oxygen sensor 1 signal
during air-fuel ratio feedback control:
RICH: means the mixture became “rich”,
and control is being affected toward a
leaner mixture.
LEAN: means the mixture became “lean”,
and control is being affected toward a rich
mixture.
After turning ON the ignition switch,
“RICH” is displayed until air-fuel mix-
ture ratio feedback control begins.

When the air-fuel ratio feedback is
clamped, the value just before the
clamping is displayed continuously. HO2S1 MNTR (B2)
[RICH/LEAN]×
HO2S2 MNTR (B1)
[RICH/LEAN]×

Display of heated oxygen sensor 2 signal:
RICH: means the amount of oxygen after
three way catalyst is relatively small.
LEAN: means the amount of oxygen after
three way catalyst is relatively large.

When the engine is stopped, a cer-
tain value is indicated.
HO2S2 MNTR (B2)
[RICH/LEAN]×
VHCL SPEED SE
[km/h] or [mph]××

The vehicle speed computed from the vehi-
cle speed signal sent from combination
meter is displayed.

TROUBLE DIAGNOSIS
EC-767
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Revision: 2004 November 2004 FX35/FX45IGN TIMING [BTDC]×
Indicates the ignition timing computed by
ECM according to the input signals.
When the engine is stopped, a cer-
tain value is indicated.
CAL/LD VALUE [%]

“Calculated load value” indicates the value
of the current air flow divided by peak air
flow.
MASS AIRFLOW
[g·m/s]

Indicates the mass air flow computed by
ECM according to the signal voltage of the
mass air flow sensor.
PURG VOL C/V [%]

Indicates the EVAP canister purge volume
control solenoid valve control value com-
puted by the ECM according to the input
signals.

The opening becomes larger as the value
increases.
INT/V TIM (B1) [°CA]

Indicates [°CA] of intake camshaft
advanced angle.
INT/V TIM (B2) [°CA]
INT/V SOL (B1) [%]

The control value of the intake valve timing
control solenoid valve (determined by ECM
according to the input signals) is indicated.

The advance angle becomes larger as the
value increases. INT/V SOL (B2) [%]
VIAS S/V
[ON/OFF]

The control condition of the VIAS control
solenoid valve (determined by ECM accord-
ing to the input signals) is indicated.

OFF: VIAS control solenoid valve is not
operating.
ON: VIAS control solenoid valve is operat-
ing.
AIR COND RLY
[ON/OFF]×

The air conditioner relay control condition
(determined by ECM according to the input
signals) is indicated.
FUEL PUMP RLY
[ON/OFF]×

Indicates the fuel pump relay control condi-
tion determined by ECM according to the
input signals.
VENT CONT/V
[ON/OFF]

The control condition of the EVAP canister
vent control valve (determined by ECM
according to the input signals) is indicated.
ON: Closed
OFF: Open
THRTL RELAY
[ON/OFF]

Indicates the throttle control motor relay
control condition determined by the ECM
according to the input signals.
COOLING FAN
[HI/OFF]

The control condition of the cooling fan
(determined by ECM according to the input
signals) is indicated.
HI: High speed operation
OFF: Stop
HO2S1 HTR (B1)
[ON/OFF]

Indicates [ON/OFF] condition of heated
oxygen sensor 1 heater determined by
ECM according to the input signals. HO2S1 HTR (B2)
[ON/OFF]Monitored item [Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks

TROUBLE DIAGNOSIS
EC-769
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
DATA MONITOR (SPEC) MODE
Monitored Item
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
ENG SPEED [rpm]××

Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS) and camshaft position
sensor (PHASE).
MAS A/F SE-B1 [V]××

The signal voltage of the mass air flow
sensor specification is displayed.
When engine is running specification
range is indicated.
B/FUEL SCHDL
[msec]×

“Base fuel schedule” indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.

When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]
A/F ALPHA-B2 [%]×

The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.
When engine is running specification
range is indicated.

This data also includes the data for the
air-fuel ratio learning control.
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION

Engine: Return to the original
trouble condition

Change the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Fuel injector

Heated oxygen sensor 1
IGNITION TIM-
ING

Engine: Return to the original
trouble condition

Timing light: Set

Retard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Perform Idle Air Volume Learning.
POWER BAL-
ANCE

Engine: After warming up, idle
the engine.

A/C switch OFF

Shift lever: N

Cut off each injector signal one at
a time using CONSULT-II.Engine runs rough or dies.

Harness and connectors

Compression

Fuel injector

Power transistor

Spark plug

Ignition coil
COOLING FAN*

Ignition switch: ON

Turn the cooling fan “HI” and
“OFF” using CONSULT-II.Cooling fan moves and stops.

Harness and connectors

Cooling fan motor

IPDM E/R
ENG COOLANT
TEMP

Engine: Return to the original
trouble condition

Change the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Engine coolant temperature sen-
sor

Fuel injector
FUEL PUMP
RELAY

Ignition switch: ON (Engine
stopped)

Turn the fuel pump relay ON and
OFF using CONSULT-II and lis-
ten to operating sound.Fuel pump relay makes the operat-
ing sound.
Harness and connectors

Fuel pump relay

EC-780
[VK45DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Revision: 2004 November 2004 FX35/FX45
TROUBLE DIAGNOSIS - SPECIFICATION VALUEPFP:00031
DescriptionABS00C01
The specification (SP) value indicates the tolerance of the value that is displayed in “DATA MONITOR (SPEC)”
mode of CONSULT-II during normal operation of the Engine Control System. When the value in “DATA MONI-
TOR (SPEC)” mode is within the SP value, the Engine Control System is confirmed OK. When the value in
“DATA MONITOR (SPEC)” mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:

B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)

A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)

MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionABS00C02

Vehicle driven distance: More than 5,000 km (3,017 miles)

Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm2 , 14.25 - 15.12 psi)

Atmospheric temperature: 20 - 30°C (68 - 86°F)

Engine coolant temperature: 75 - 95°C (167 - 203°F)

Transmission: Warmed-up*1

Electrical load: Not applied*2

Engine speed: Idle
*1: After the engine is warmed up to normal operating temperature, drive vehicle until “FLUID TEMP SE” (A/T
fluid temperature sensor signal) indicates more than 60°C (140°F).
*2: Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection ProcedureABS00C03
NOTE:
Perform “DATA MONITOR (SPEC)” mode in maximum scale display.
1. Perform EC-733, "
Basic Inspection" .
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2”
and “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode with
CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-781, "
Diagnostic Procedure" .
SEF601Z

EC-814
[VK45DE]
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
Revision: 2004 November 2004 FX35/FX45
DTC P0037, P0038, P0057, P0058 HO2S2 HEATERPFP:226A0
DescriptionABS00C0V
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeABS00C0W
Specification data are reference values.
On Board Diagnosis LogicABS00C0X
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600OFF
Below 3,600 rpm after the following conditions are met.

Engine: After warming up

Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no loadON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)

Engine speed is below 3,600 rpm after the following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no loadON

Engine speed: Above 3,600 rpm OFF
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0037
0037
(Bank 1)Heated oxygen
sensor 2 heater
control circuit lowThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)

Harness or connectors
(The heated oxygen sensor 2 heater circuit is
open or shorted.)

Heater oxygen sensor 2 heater P0057
0057
(Bank 2)
P0038
0038
(Bank 1)Heated oxygen
sensor 2 heater
control circuit highThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to
ECM through the heated oxygen sensor 2
heater.)

Harness or connectors
(The heated oxygen sensor 2 heater circuit is
shorted.)

Heater oxygen sensor 2 heater P0058
0058
(Bank 2)